Beehiiv

Beehiiv is a newsletter platform with a REST API for programmatic subscriber management, post creation, and publication analytics. For agents, relevant capabilities include: adding/removing subscribers, checking subscription status, fetching publication metrics, creating and scheduling newsletter posts. Useful for content agent pipelines that need to manage newsletter audiences or publish content automatically. The API is focused on Beehiiv's core newsletter workflows — not a general-purpose email sending API like Resend or Postmark. Good fit for media-adjacent agent workflows. Confidence is docs-derived.

API key auth via Authorization: Bearer header. Keys are per-publication (each newsletter is a separate publication). No fine-grained scope system within the key; keys have full publication access. Key rotation via Beehiiv dashboard under API settings. HTTPS enforced. Webhook signature verification for event consumers.

REST API at api.beehiiv.com/v2. Resources: publications, subscriptions, subscribers, posts, automation, segments. CRUD operations on subscribers and posts. Pagination via page and limit params. Subscription creation includes custom_fields support for enriched subscriber data. Response envelopes: {data: {...}, meta: {...}} pattern with total_results and pagination info. Webhook support for subscription events.

Structured JSON error responses with HTTP status codes. 401 for invalid API key, 404 for missing publication/subscriber, 422 for validation errors (with field-level detail). Rate limits documented per API key (requests per minute). Delivery of newsletter emails handled by Beehiiv's infrastructure; sending reliability depends on Beehiiv's email delivery partnerships. No published SLA for the API tier.

developers.beehiiv.com/docs provides API reference organized by resource type, authentication guide, and webhook documentation. Code examples available in the docs. Getting started requires a Beehiiv account with API access enabled (available on paid plans). Documentation quality is adequate; covers core use cases clearly. Community support via Beehiiv's creator community.